You get used to the radio not being able to be turned off in the 8.4. I just turn my volume down to zero (not using mute button) before I turn off the truck. Not hard, just different. No more different than getting used to a turn knob for a shifter, which I still find cool.
Some Rams do come with a full size spare. My father's 2015 Laramie came with a temp spare, he was a bit upset. My Longhorn came with a full size, and I currently have an oversized spare in there to match my slightly oversized tires (275/65R20). It does fit.